I've never made a pick up but I like the look of the correct number of poles to strings (Ya OCD is strong within me) which is why I'm  thinking I want to make a humbucker pick up with 3 or 4 poles.

First I need some clarification on Pup anatomy, a single coil the pole pieces are the the magnets vs the steel slugs and a bar mag in the bottom of a HB, Right?

In my thinking I'm wondering about the effect of a shortened bobbin on the length of wire used. While the # of wraps would stay the same it it will use less wire thus give less resistance right? Is this going to effect the field enough to worry about perhaps needing to overwind?

 How much of an effect do you think shortening the magnet will cause? I know magnets are tough to cut, that's a hurdle I'll have to overcome and worry about either weakening or killing it all together in the process. I've also though of just finding the right size magnets but that maybe cost prohibitive. Which leads me to the thoughts of using neodymium because I've actually found some in what I think would be the correct size.  Any thoughts on this part would greatly appreciated.

I'm sure I'll have more questions but these are the ones I've come up with so far.